The Arizona Cancer Center (ACC) Cytogenetics Shared Service provides genetic characterization of normal and malignant cells in support of ACC research and collaborations, such as those with the National Human Genome Research Institute. Services include karyotyping and detailed chromosome analysis using fluorescence in situ hybridization (FISH). These services identify genetic abnormalities for detailed study and are an important quality control for cell lines. A database for prior karyotypes and FISH results is maintained and allows this shared services to compare current and past results to detect potential contaminants and detect genetic "drift" in selected cell lines. By interfacing these results with resources of the Tissue Cultured Shared Service, unique cell lines developed by the ACC and "public" cell lines with specific genetic abnormalities can be identified and provided to ACC investigators. The Cytogenetic Shared Service is the only facility providing detailed chromosome characterization of malignant cell on the Arizona Health Sciences Campus.